java使用代理訪問網路

在使用java的net包訪問網路時，如果需要使用代理，可以這樣做：

    System.getProperties().setProperty("proxySet", "true");    System.getProperties().setProperty("http.proxyHost", "183.121.23.188");    System.getProperties().setProperty("http.proxyPort", "8080");    URL url = new URL(http://www.163.com);    HttpURLConnection httpConn = (HttpURLConnection)url.openConnection();    HttpURLConnection.setFollowRedirects(true);    httpConn.setRequestMethod("GET");    httpConn.setRequestProperty("User-Agent","Mozilla/4.0 (compatible; MSIE 6.0; Windows 2000)");    InputStream in = httpConn.getInputStream();    BufferedReader myBufferedReader=new BufferedReader(new InputStreamReader(in));    String myString=null;    while((myString=myBufferedReader.readLine())!=null){        System.out.println(myString);    }

其中，前三行就是設定代理的語句。